scholarly journals Enterococcus, Myroides Y Exiguobacterium: GÉNEROS BACTERIANOS CON POTENCIAL PROBIÓTICO PARA EL CULTIVO DE TILAPIA NILÓTICA (Oreochromis niloticus)

2017 ◽  
Vol 22 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Luisa Marcela Villamil Díaz ◽  
Daniel Esguerra Rodríguez
Keyword(s):  
16S Rrna ◽  
Enterococcus Faecalis ◽  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Edwardsiella Tarda ◽  
Tilapia Nilotica ◽  
Myroides Odoratimimus

Se aislaron 120 morfotipos bacterianos de intestino de tilapia y se seleccionaron según su actividad antibacteriana contra patógenos como Aeromonas hydrophila, Streptococcus agalactiae y Edwardsiella tarda, su capacidad de adherencia a mucus intestinal y cinética de crecimiento. Las bacterias seleccionadas se identificaron mediante secuenciación de 16S rRNA y se identificaron como Exigobacterium sp. I9, Enterococcus faecalis I15 y Myroides odoratimimus I19. Además, se evaluó su efecto in vivo sobre el crecimiento de los peces, mediante su adición al alimento de juveniles de Oreochromis niloticus (106 UFC / g, por 15 días). Se determinó la supervivencia luego de un desafío experimental con Edwardsiella tarda por inyección intraperitoneal (100 µL 105 UFC / mL). Las tres bacterias seleccionadas incrementaron la tasa de crecimiento específica, redujeron la mortalidad de los peces durante el desafío experimental con E. tarda y no causaron mortalidad durante la adición en el alimento. Los efectos positivos in vivo se relacionan posiblemente con actividad in vitro; sin embargo, por motivos de bioseguridad se recomienda efectuar estudios posteriores a Exigobacterium sp. I9y E. faecalis I15 dado que se han reportado miembros de este género como causantes de mortalidad en peces, mientras que en el caso de M. odoratimimus I19, es necesario efectuar futuros estudios para verificar su actividad positiva a mayor escala productiva.

In vitro and in vivo screening of herbal extracts against Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus)

Aquaculture ◽  
2019 ◽  
Vol 503 ◽  
pp. 412-421 ◽  
Author(s):  
Wei-Liang Guo ◽  
Heng-Wei Deng ◽  
Fei Wang ◽  
Shi-Feng Wang ◽  
Zhi-Hong Zhong ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Herbal Extracts ◽  
In Vivo Screening ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals PENAMBAHAN KANDIDAT PROBIOTIK Bacillus methylothrophicus SECARA BERKALA PADA MEDIA PEMELIHARAAN UNTUK PENCEGAHAN INFEKSI BAKTERI Aeromonas hydrophila PADA IKAN NILA (Oreochromis niloticus)

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Femy Musthofa Ardy ◽  
Desrina Desrina ◽  
Alfabetian Harjuno Condro Haditomo
Keyword(s):  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Pathogenic Bacteria ◽  
Survival Rates ◽  
Average Weight ◽  
In Vitro Test ◽  
In Vivo Test ◽  
Short Period

Aeromonas hydrophila is a bacteria that causes of MAS disease (motile aeromonad septicemia) in freshwater fish cultivation and can cause mass death in a fairly short period of time in some species including tilapia. There are several alternative strategies in prevention, one of which is the use of probiotic bacteria as agents for controlling or preventing this disease. One candidate for probiotics that has been molecularly identified as 16sRNA and is known to have the ability to inhibit pathogenic bacteria is B. methylotrhrophicus. The aim of this research was to study B.methylotrophicus in inhibiting  A. hydrophila in Oreochromis niloticus culture. This research consisted of in vitro and in vivo test that used experiment method with completely randomized design with 4 treatments (density of 1 fishes/l) and 3 replications. The treatment consisted of a mixture of A. hydrophila 102 CFU/mL with B. methylotrophicus 109 CFU/mL (a) without addition of B. methylotrophicus (b) Addition every 3 days, (c) Addition every 5 days, (d) Addition every 7 day. 120 fishes at average weight of 17,5±1,9 g was used as experimental animals. Based on the in vitro test, the most powerful concentration of B. methylotrophicus to inhibit A. hydrophila was 109 cfu/mL with clear zone of 24,9±4,2 mm. In vivo tests show that the addition of B. methylotrophicus periodecally does not significantly affect survival rates, but can slow the gowth of A. hydrophila. Treatment D showed the highest survival rate (13.33%), followed by treatment A (6.66%), B (3.33%), and C (3.33%). These results indicate that B.methylotrophicus can prevent the gowth of A. hydrophila in vitro, and can increase SR by 6.66% in the in vivo test.

scholarly journals Enterococcus faecalis exploits the human fibrinolytic system to drive excess collagenolysis: implications in gut healing and identification of druggable targets

2020 ◽  
Vol 318 (1) ◽  
pp. G1-G9 ◽  
Author(s):  
Richard A. Jacobson ◽  
Kiedo Wienholts ◽  
Ashley J. Williamson ◽  
Sara Gaines ◽  
Sanjiv Hyoju ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Healing Process ◽  
Abdominal Sepsis ◽  
Infectious Complications ◽  
Fibrinolytic System ◽  
Clinical Safety ◽  
High Concentrations ◽  
Clinically Significant

Perforations, anastomotic leak, and subsequent intra-abdominal sepsis are among the most common and feared complications of invasive interventions in the colon and remaining intestinal tract. During physiological healing, tissue protease activity is finely orchestrated to maintain the strength and integrity of the submucosa collagen layer in the wound. We (Shogan, BD et al. Sci Trans Med 7: 286ra68, 2015.) have previously demonstrated in both mice and humans that the commensal microbe Enterococcus faecalis selectively colonizes wounded colonic tissues and disrupts the healing process by amplifying collagenolytic matrix-metalloprotease activity toward excessive degradation. Here, we demonstrate for the first time, to our knowledge, a novel collagenolytic virulence mechanism by which E. faecalis is able to bind and locally activate the human fibrinolytic protease plasminogen (PLG), a protein present in high concentrations in healing colonic tissue. E. faecalis-mediated PLG activation leads to supraphysiological collagen degradation; in this study, we demonstrate this concept both in vitro and in vivo. This pathoadaptive response can be mitigated with the PLG inhibitor tranexamic acid (TXA) in a fashion that prevents clinically significant complications in validated murine models of both E. faecalis- and Pseudomonas aeruginosa-mediated colonic perforation. TXA has a proven clinical safety record and is Food and Drug Administration approved for topical application in invasive procedures, albeit for the prevention of bleeding rather than infection. As such, the novel pharmacological effect described in this study may be translatable to clinical trials for the prevention of infectious complications in colonic healing. NEW & NOTEWORTHY This paper presents a novel mechanism for virulence in a commensal gut microbe that exploits the human fibrinolytic system and its principle protease, plasminogen. This mechanism is targetable by safe and effective nonantibiotic small molecules for the prevention of infectious complications in the healing gut.

scholarly journals Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Bacillus Licheniformis ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Carassius Auratus ◽  
Quorum Quenching ◽  
Inhibition Rate ◽  
Sequence Identity

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.

scholarly journals Two-Step Acquisition of Resistance to the Teicoplanin-Gentamicin Combination by VanB-Type Enterococcus faecalis In Vitro and in Experimental Endocarditis

1999 ◽  
Vol 43 (3) ◽  
pp. 476-482 ◽  
Author(s):  
Agnès Lefort ◽  
Marina Baptista ◽  
Bruno Fantin ◽  
Florence Depardieu ◽  
Michel Arthur ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Acquired Resistance ◽  
Simultaneous Acquisition ◽  
Resistant Mutants

ABSTRACT The activity of vancomycin and teicoplanin combined with gentamicin was investigated in vitro against strains of Enterococcus faecalis resistant to vancomycin and susceptible to teicoplanin (VanB type) and against mutants that had acquired resistance to teicoplanin by three different mechanisms. In vitro, gentamicin selected mutants with two- to sixfold increases in the level of resistance to this antibiotic at frequencies of 10−6 to 10−7. Teicoplanin selected teicoplanin-resistant mutants at similar frequencies. Both mutations were required to abolish the activity of the gentamicin-teicoplanin combination. As expected, simultaneous acquisition of the two types of mutations was not observed. In therapy with gentamicin or teicoplanin alone, each selected mutants in three of seven rabbits with aortic endocarditis due to VanB-type E. faecalis BM4275. The vancomycin-gentamicin combination selected mutants that were resistant to gentamicin and to the combination. In contrast, the teicoplanin-gentamicin regimen prevented the emergence of mutants resistant to one or both components of the combination. These results suggest that two mutations are also required to suppress the in vivo activity of the teicoplanin-gentamicin combination.

Effects of Enterococcus faecalis UGRA10 and the enterocin AS-48 against the fish pathogen Lactococcus garvieae. Studies in vitro and in vivo

2019 ◽  
Vol 77 ◽  
pp. 69-77 ◽  
Author(s):  
Alberto Baños ◽  
Juan José Ariza ◽  
Cristina Nuñez ◽  
Lidia Gil-Martínez ◽  
J. David García-López ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Fish Pathogen ◽  
Lactococcus Garvieae

Degradation of trimethylamine in vitro and in vivo by Enterococcus faecalis isolated from healthy human gut

2018 ◽  
Vol 135 ◽  
pp. 24-32
Author(s):  
Yi-ran Chen ◽  
Shu-ting Fang ◽  
Hai-yue Liu ◽  
Hui-min Zheng ◽  
Yan He ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Human Gut ◽  
Healthy Human
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